This invention relates generally to data centers, and more particularly to providing backup power to the servers and/or other critical systems in a data center.
Organizations often employ data centers to manage their data processing and other computing needs. A data center typically houses many racks of servers, which together perform the processing tasks that a single machine could not. The role of a data center is often critical to an organization, and downtime of a data center can result in severe consequences to the organization and to others who rely on the data center. Since power failures are not uncommon, data centers use power backup systems to deal with interruptions in the supply of power from utility services, which would otherwise result in downtime.
When the utility power goes down, a data center typically uses a power backup system to provide emergency power to computing and other critical resources, such as cooling systems (e.g., an HVAC and chillers). In a typical data center, the backup power is provided by a combination of diesel generators and an uninterrupted power supply (UPS). The UPS is placed between an input power terminal from a utility service and one or more power distribution units (PDUs) in the data center, to which the servers are connected. When the utility power is functioning properly, the UPS uses a portion of the utility power to charge a battery within the UPS, and the majority of the remaining power from the utility service is passed along for use by the data center site. When an interruption in the utility power occurs, the UPS provides temporary backup power to the site for a sufficient period of time to allow the diesel generators to be turned on (typically, 8 to 10 seconds). Once the diesel generators have started, they produce electrical power for the site until normal utility power is reestablished.
A principal drawback of the design of a standard data center is the use of diesel generators. There are many problems with diesel power, both economic and environmental. For example, a substantial number of generators and a large diesel fuel store are required to power a typical data center. Therefore, diesel power generation involves substantial expenditures for generators, fuel stores (which require a polishing system to keep the fuel from being contaminated), and maintenance of this equipment. In addition to economic concerns, there are environmental drawbacks (which also result in further economic expenditures), such as diesel emissions compliance, permits, fire codes with respect to the fuel stores, fumes contaminating the data center, etc.
Accordingly, it would be desirable to provide a backup power system for data centers that reduces or eliminates the need for diesel generators to supply backup power to one or more of the systems in a data center that require power.